Time-restricted feeding alleviates heat stress-induced liver ferroptosis in piglets via nuclear receptor NR1D1-mediated transcription modulation.

Heat stress (HS) disturbs hepatic metabolic homeostasis and redox balance, compromising antioxidant capacity and mitochondrial function. Ferroptosis, a lipid peroxidation-associated form of regulated cell death, has been implicated in redox-sensitive metabolic disorders. Whether nutritional timing influences HS-associated ferroptotic responses in the liver remains unclear. This study examined the effects of time-restricted feeding (TRF) on hepatic redox regulation and ferroptosis-related molecular pathways under chronic heat exposure. Piglets were exposed to cyclic heat challenge (35°C, 4 h/d) for 65 days with or without TRF intervention. Hepatic oxidative status, mitochondrial function, and ferroptosis-associated gene and protein expression were evaluated using biochemical assays, transcriptomic analysis, RT-qPCR, western blotting, and chromatin immunoprecipitation. Chronic heat exposure was associated with decreased hepatic glutathione levels, increased lipid peroxidation, reduced antioxidant enzyme activities, impaired mitochondrial ultrastructure, and lower ATP production (P<.05). Transcriptomic profiling revealed coordinated changes in ferroptosis-related genes, including increased TFRC, ACSL4, and HMOX1 expression and decreased GPX4, SLC7A11, and NFE2L2 expression (P<.05). Heat exposure was accompanied by elevated NR1D1 expression and altered promoter occupancy at redox-related genes. TRF partially restored antioxidant status, improved mitochondrial integrity, attenuated ferroptosis-associated transcriptional alterations, and modulated NR1D1 expression patterns (P<.05). These findings suggest that chronic HS is associated with hepatic redox disruption and ferroptosis-related molecular changes. TRF may mitigate these metabolic disturbances through modulation of redox-sensitive transcriptional regulation.